Green design and manufacturing decisions: A case study in ground surfaces

Incorporating environmental performance considerations into concurrent product design and manufacturing process development requires analysis of the complex mechanistic interplay among engineering, manufacturing, and environmental performance. This dissertation presents a hierarchical framework supporting modular development of three levels of green decision support tools to facilitate such an analysis. The analytical foundation of these tools is the unit process model.;Machining was selected as the process of focus because of its pervasiveness and because trade-offs between environmental and manufacturing performance are of major concern. Surface finish through grinding is of particular interest in this context because first, grinding is associated with a higher level of health and environmental effects than other machining processes; and second, surface finish can in some cases be a functional parameter, potentially leading to design tradeoffs between functional and environmental performance. The grinding model consists of a system of sub-models, including: an energy sub-model based on chip formation energy and friction losses; a fluid vaporization sub-model based on bulk heating; a wheel wear sub-model based on cutting force-dependent probabilistic grain fracture; a liquid carry-off sub-model based on surface tension; and finally, a fluid aerosol sub-model based on breakup of fluid ejected from the grinding wheel. Energy use and material waste flows are important environmental parameters. Because cutting fluid aerosol is of particular health concern, persistence-weighted aerosol is also considered as a separate parameter. A multi-criteria hazard evaluation is also used to apply a hazard weighting to the process waste mass. These parameters are used to evaluate process environmental performance through a utility formulation or graphical constraint-based analysis.;The first type of tool supports process planning. For process planning (microplanning), the manufacturing process parameters, cutting fluid, and grinding wheel are selected, as constrained by the surface specification for the given feature, such that the environmental parameters are optimized. The developed process planning software is also integrated into a larger computer-aided process planning software tool that performs part level optimization (macroplanning). As the type of tool used for these tasks is utilized late in the component design process, its main purpose is to environmentally optimize the manufacturing process for a given component design.;The second type of tool informs component design decisions. Tools were constructed to analyze functional and environmental performance trade-offs for journal, roller, and hydrostatic bearings. For these tools, analytical relationships between ground surface finish and bearing functional performance are combined with the basic process model and environmental evaluation module. Developed tools graphically highlight component functional and manufacturing environmental performance trade-offs in the parameter space region of interest.;The third type of tool supports more general system evaluation and more strategic process development. These tools support facility-level fluid selection, and also provide guidance for fluid developers seeking to specify desired fluid properties and/or to evaluate environmental performance for new fluid formulations. For both of these sets of tools, a graphical scheme was devised to evaluate process environmental performance and decision robustness for a set of current and hypothetical future environmental constraints for a given fluid. (Abstract shortened by UMI.)...